(a) Field of the Invention
The present invention relates to a jet spray nozzle for cleaning machine and more particularly to a pressure-adjustable jet spray nozzle, which allows adjustment of the pressure of the jet spray water or cleaning fluid during operation and also allows replacement of the nozzle head.
(b) Description of the Prior Art
Conventional high-pressure cleaning machines commonly use a motor or engine to drive a pump in pumping compressed clean water or cleaning fluid to a water pipe that has a jet spray nozzle at the free end. A user can control a control level of the jet spray nozzle to let compressed clean water or cleaning fluid be driven out of the nozzle tip of the jet spray nozzle for cleaning. However, a conventional jet spray nozzle, for example, the ejection nozzle for high-pressure and lower-pressure cleaning apparatus as disclosed in U.S. Pat. No. 5,242,116, simply allows adjustment of the pressure of output water or cleaning fluid. It does not allow replacement of the nozzle head by the user. There is known a jet spray nozzle that allows replacement of the nozzle head. However, this design of jet spray nozzle is for use to spray gasoline. The nozzle head and other component parts of this design of jet spray nozzle are made of metal. Thus, the manufacturing cost of this design of jet spray nozzle is relatively high. Because of the relatively high cost, this design of jet spray nozzle is not suitable for use with a high-pressure cleaning apparatus for ejecting clean water or cleaning fluid for cleaning.
Therefore, there is a strong need for an inexpensive jet spray nozzle that allows replacement of the nozzle head.